Update to 2.0.24.
Fixup the if_ and if_errcoll_ plugins, interface names can be longer than 5
chars. Add an if_packets_ plugin.
Allow people to have a custom crontab that won't be touched when
installing/deinstalling.
Sponsored by: Absolight

- update to 2.0.7
- move USERS and GROUPS from munin-common/Makefile to munin.mk, otherwise they
cannot be used in the Makefiles of munin-master and munin-node where they are
required. This fixes permissions on certain directories. [1]
- VERSION.node file should be updated after the pkg-install script runs, because
it requires the version of the previously installed version not the currently
installed one. [2]
PR: ports/172260 [1]
Reported by: Haruo Shiba <shiba@logic-design.co.jp> [1]
tdb [2]

Continue rototilling the Munin ports:
- Move some files around and adjust the plists accordingly.
- Fix some directory creation / deletion in the plists.
- Fix some directory ownerships.
- Instead of patching the Makefile, specify installation directories
on the command line. Centralize the definition of MAKE_ARGS and some
other shared variables.
Feature safe: yes